Epson LX-80, Operating Manual

Page: 180 / 193

4 . D a t a transfer must be carried out by observing the ACKN LG or
BU SY s i g nal . (Data transfer to this printer can be ca rr i ed out
o n ly a f ter receipt of the ACKNLG signal or when the l eve l of the
B USY sig nal is LOW.)
5. U nder n o rmal conditions , printer cable pins 11 , 12 , and 32 are
activate d w hen the paper-end condition is detected. Th e <ESC>
8 code dis ables pins 11 and 32 , but not pin 12. Those com p u ters
that moni tor pin 12 halt printing when the paper is out , m aking
<ESC> 8 ineffective .
I nt e r f a ce timing
Figure I - I sho ws the timing for th e parallel interface .
DA TA
S T ROBE
BUSY
A CKNL G
0.5
J1S
Imin.)
0.5
J1S
Imin . l
0.5
J1S
Imin.)
Approx. 5
J 1S
Approx. 7
J 1S
S i g n a l re l a tionships
Tab l e 1-2 s h o ws the way data entry is handled in the on-l ine and
off- li ne states by showing the relationships between sev e n sign a l
sets .
On-Line SLCTIN ERROR BUSY ACKNLG DATA ENTR Y
OFF HI G H / LOW LOW HIGH Not generated Disabled
ON HI G H HIGH LOW / HIGH Generated after data entry Enabled '
ON L O W HIGH Same Same Enabled (norm a l entr y)
*Whe n S L C T IN is at high level, data entry is enabled, but th e input
da t a wi ll be disregarded until SLCT IN is at low level .
Note : ERROR status is assumed to rest only in off-line st a t e, and
the E RROR status does not always mean SLCT IN.